Quality is Job 1. In the Beginning… Deming – the name of quality Think of autos In software...
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Transcript of Quality is Job 1. In the Beginning… Deming – the name of quality Think of autos In software...
Quality is Job 1
In the Beginning…
• Deming – the name of quality
• Think of autos
• In software– Program mistakes– Development time– Originally inspect final product; identify
errors; and then work to repair damage
In a Modern System
• Now…– Design a quality system up front– Build quality into the product– Filter out errors as early in the project as
soon as detected– Also – define the level of quality that is
desired
A Balance…
• Must be reached between quality and resources
• Processes should be continually improved along the way
In PMBOK
• Quality Planning
• Perform Quality Assurance (user requirements)
• Perform Quality Control (meets standards and eliminate unsatisfactory performance)
10 Principles for Quality in Software
Following the principles will generally ensure quality in your software
Principle 1-Use Feedback
• Defect Prevention Process (DPP) = Software Engineering Institute's Capability Maturity Model (CMM) Level 5
• Inspection Method – IBM
• Evolutionary Project Management
• Statistical Control
Principle 2 – Identify Critical Measures
• For each critical factor you would find a series of faults that would include the following: failure to..– Systematically identify all critical
stakeholders and their critical needs– Define the factor measurable– Define a practical way to measure the factor– Contract measurably for the critical factor
Cont…
• Design toward reaching the factor’s critical levels
• Make the entire project ream aware of the numeric levels needed for the critical factors
• Maintain critical levels of performance during peak loads or on system growth
• As a matter of fact most quality factors are not defined quantitatively at all (only performance, budget and deadlines are) (Others that are not defined are serviceability, reliability, adaptability, portability and usability)
Principle 3 – Control Multiple Objectives
• Must be able to deal with all critical factors simultaneously
• Use Impact Estimation Table – tracking estimation against goals
• When deviations are noted then you can control immediately for them
Impact Estimation TableStep 1
Plan 1
Step 1
Actual
Step 1
Difference
Step 1
Total
Step 2 and so forth ….
Reliability 50%
+_ 50%40% -10% 40%
Continue on with totals for cumulative stepsPerformance
11 sec-1 sec
80%
+- 40%40% -40% 40%
Usability
30 min-30 sec10%-
+_20%12% +2% 12%
Capital Cost
1 million20% -+_10%
10% +10% 10%
Programming Hrs 10,000
2%-+-1%
4% -2% 4%
Calendar Time 1 wk 2 wk -1 wk 1 wk
Principle 4 – Evolve in Small Steps
• Dealing with the unknown and risk
• Goal is to deal with development in small steps
• Not necessarily modules, but those items that satisfy stakeholders
• May be as small as a day or week
Principle 5 – A Stitch in Time Saves Nine
• Need strong specification standards
• Keep reducing minimum until acceptable
• Use inspection sampling to reduce errors
Principle 6 – MotivationMoves Mountains
• Four categories of problems– Will to change– Knowledge to change direction – channel energies
• Measurable, quantified clarity of the requirements and objectives of various stakeholders (people generally unclear about goals and no ability to get numeric feedback)
• Knowledge of all the multiple critical goals (focus too much on one goal and not on all)
• Formal awareness of constraints such as resources and laws– Ability to change– Feedback about progress in the desired change
direction
Principle 7 – Competitionis Eternal
“We have an infinite set of milestones or evolutionary steps of result delivery and use them as we need; the moment we abandon a project, we hand opportunity to our competitors. They can sail past our levels of performance and take our markets.”
Principle 8 – Things Take Time
• “It takes two to three years to change a project, and a generation to change a culture.”
• There needs to be a long-term plan with visible short-term progress.
Principle 9 – The Bad with the Good
You must have– A quantified, multidimensional specification of our
requirements, our quality objectives, and our resources (people, time, $$)
– Knowledge of the expected impact of each design idea on all these quality objectives and resources
– Evaluate each design idea with respect to its total – expected or real – impact on requirements, unmet objectives and the unused cost budgets
Principle 10 – Keep Your Eyes on Where You Are Going
• To discover the real problem – ask of a specification – Why?
• Task is to design and deliver high quality software that meets the specifications!
• Keep people motivated!